What Actually Goes in a Functional Specification? – Brilliant article outlining one of the main outputs of my job. This matches exactly my thinking on the subject. I do cater the Func Spec to the project and audience. On a purely internal project, I leave a lot of the UI behaviour up to the developers because I trust them to use the most efficient option. On a project for an external client though, I get a lot more specific in the details. My Specs are mainly done as Google Docs, but I’m experimenting with some prototyping tools now.